1 /*
2 * Copyright (c) 2003 The Visigoth Software Society. All rights
3 * reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
15 * distribution.
16 *
17 * 3. The end-user documentation included with the redistribution, if
18 * any, must include the following acknowledgement:
19 * "This product includes software developed by the
20 * Visigoth Software Society (http://www.visigoths.org/)."
21 * Alternately, this acknowledgement may appear in the software itself,
22 * if and wherever such third-party acknowledgements normally appear.
23 *
24 * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
25 * project contributors may be used to endorse or promote products derived
26 * from this software without prior written permission. For written
27 * permission, please contact visigoths@visigoths.org.
28 *
29 * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
30 * nor may "FreeMarker" or "Visigoth" appear in their names
31 * without prior written permission of the Visigoth Software Society.
32 *
33 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
34 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
35 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
36 * DISCLAIMED. IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
37 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
38 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
39 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
40 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
41 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
42 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
43 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44 * SUCH DAMAGE.
45 * ====================================================================
46 *
47 * This software consists of voluntary contributions made by many
48 * individuals on behalf of the Visigoth Software Society. For more
49 * information on the Visigoth Software Society, please see
50 * http://www.visigoths.org/
51 */
52
53 package freemarker.core;
54
55 import java.io.IOException;
56 import java.util.ArrayList;
57 import java.util.Collection;
58
59 import freemarker.template.SimpleNumber;
60 import freemarker.template.TemplateBooleanModel;
61 import freemarker.template.TemplateCollectionModel;
62 import freemarker.template.TemplateException;
63 import freemarker.template.TemplateModel;
64 import freemarker.template.TemplateModelIterator;
65 import freemarker.template.TemplateSequenceModel;
66
67 /**
68 * An instruction that processes a list or foreach block
69 */
70 final class IteratorBlock extends TemplateElement {
71
72 private Expression listExpression;
73 private String indexName;
74 private boolean isForEach;
75
76 /**
77 * @param listExpression a variable referring to a sequence or collection
78 * @param indexName an arbitrary index variable name
79 * @param nestedBlock the nestedBlock to iterate over
80 */
81 IteratorBlock(Expression listExpression,
82 String indexName,
83 TemplateElement nestedBlock,
84 boolean isForEach)
85 {
86 this.listExpression = listExpression;
87 this.indexName = indexName;
88 this.isForEach = isForEach;
89 this.nestedBlock = nestedBlock;
90 }
91
92 void accept(Environment env) throws TemplateException, IOException
93 {
94 TemplateModel baseModel = listExpression.getAsTemplateModel(env);
95 if (baseModel == null) {
96 if (env.isClassicCompatible()) {
97 // Classic behavior of simply ignoring null references.
98 return;
99 }
100 assertNonNull(baseModel, listExpression, env);
101 }
102 env.visit(new Context(baseModel));
103 }
104
105 public String getCanonicalForm() {
106 if (isForEach) {
107 StringBuffer buf = new StringBuffer("<#foreach ");
108 buf.append(indexName);
109 buf.append(" in ");
110 buf.append(listExpression.getCanonicalForm());
111 buf.append(">");
112 if (nestedBlock != null) {
113 buf.append(nestedBlock.getCanonicalForm());
114 }
115 buf.append("</#foreach>");
116 return buf.toString();
117 }
118 else {
119 StringBuffer buf = new StringBuffer("<#list ");
120 buf.append(listExpression.getCanonicalForm());
121 buf.append(" as ");
122 buf.append(indexName);
123 buf.append(">");
124 if (nestedBlock != null) {
125 buf.append(nestedBlock.getCanonicalForm());
126 }
127 buf.append("</#list>");
128 return buf.toString();
129 }
130 }
131
132 public String getDescription() {
133 if (isForEach) {
134 return "foreach " + indexName + " in " + listExpression;
135
136 }
137 else {
138 return "list " + listExpression + " as " + indexName;
139 }
140 }
141
142 /**
143 * A helper class that holds the context of the loop.
144 */
145
146 class Context implements LocalContext {
147 private boolean hasNext;
148 private TemplateModel loopVar;
149 private int index;
150 private Collection variableNames = null;
151 private TemplateModel list;
152
153 Context(TemplateModel list) {
154 this.list = list;
155 }
156
157
158 void runLoop(Environment env) throws TemplateException, IOException {
159 if (list instanceof TemplateCollectionModel) {
160 TemplateCollectionModel baseListModel = (TemplateCollectionModel)list;
161 TemplateModelIterator it = baseListModel.iterator();
162 hasNext = it.hasNext();
163 while (hasNext) {
164 loopVar = it.next();
165 hasNext = it.hasNext();
166 if (nestedBlock != null) {
167 env.visit(nestedBlock);
168 }
169 index++;
170 }
171 }
172 else if (list instanceof TemplateSequenceModel) {
173 TemplateSequenceModel tsm = (TemplateSequenceModel) list;
174 int size = tsm.size();
175 for (index =0; index <size; index++) {
176 loopVar = tsm.get(index);
177 hasNext = (size > index +1);
178 if (nestedBlock != null) {
179 env.visit(nestedBlock);
180 }
181 }
182 }
183 else if (env.isClassicCompatible()) {
184 loopVar = list;
185 if (nestedBlock != null) {
186 env.visit(nestedBlock);
187 }
188 }
189 else {
190 throw invalidTypeException(list, listExpression, env, "collection or sequence");
191 }
192 }
193
194 public TemplateModel getLocalVariable(String name) {
195 if (name.startsWith(indexName)) {
196 switch(name.length() - indexName.length()) {
197 case 0:
198 return loopVar;
199 case 6:
200 if(name.endsWith("_index")) {
201 return new SimpleNumber(index);
202 }
203 break;
204 case 9:
205 if(name.endsWith("_has_next")) {
206 return hasNext ? TemplateBooleanModel.TRUE : TemplateBooleanModel.FALSE;
207 }
208 break;
209 }
210 }
211 return null;
212 }
213
214 public Collection getLocalVariableNames() {
215 if(variableNames == null) {
216 variableNames = new ArrayList(3);
217 variableNames.add(indexName);
218 variableNames.add(indexName + "_index");
219 variableNames.add(indexName + "_has_next");
220 }
221 return variableNames;
222 }
223 }
224 }
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